Question about Universe

[Shaw]

I guess this is what's confusing me.

Are you saying that space wasn't expanding uniformly...

Well, I didn't address that at all, but for the sake of this example, let say it was at this point in the model.

or just that matter wasn't being uniformly 'dragged' along through space because in some places it was more gravitationally bound together?

I'm saying that it is reasonable to expect that in this period of almost unimaginably dense matter/energy that the distribution of that matter/energy would be uniform throughout the entire volume of the universe. The uniform distribution of matter/energy everywhere in the universe negates the effects of gravitation everywhere.

The only way for gravitation to take effect on that matter/energy would be for the braking of that symmetry.

I'm not sure that symmetry braking isn't as hard a concept for some people to grasp as a finite volume universe. I've seen some people have a hard time with concepts that at first I thought were pretty straight forward.

Besides, certain things (like time and velocity) break down at very small distances. So until the universe was of a reasonable size, things like gravity, the speed of light and even before and after aren't well defined.

But at a stage where these things would be well defined, certain aspects (like gravity) can't come into play until at some point in space the matter/energy distribution is different from the rest of the universe (basically, clumping)... that would be the foot hold gravity would need to get it's start in the universe.

Again, one need only look at the universe as we have mapped it so far to see the web like structures formed by galaxies. They aren't randomly (or evenly) distributed. The pattern they display echo's the braking of symmetry in the early universe.


Sadly, these subjects generally lead down one path... at some point posting in a thread can't answer a question that takes years of course work and study to have reached an understanding of that answer in the first place. It is easy to forget what it took to reach a certain understanding and then get frustrated when a handful of words doesn't convey the meaning one would hope. All too often answers rely on a previous understanding of other topics just as deep as the one being asked about.

 

[Jadzia]

I think that would be quite straight forward to simulate, for say a hypersphere.

We can populate a hypersphere with mutually repelling particles, and evolve it to find a least energy solution. That corresponds to a uniform gravity, as each particle is in equilibrium.

We then switch to attracting forces, and create a minor disturbance, to break the symmetry, and watch how the uniform density becomes shattered.

I can make some pictures too

A little project for this afternoon.

 

[pimp]

lol i am now left even more confused

The Universe is roughly 13 billion years old, ok I'm cool with this number but how they figure it out???

secondly:

When the Hubble space telescope took those pictures of the furthest galaxies in 2004 (i think) those galaxies where 13 billion years old but were much further than 13 billion light years away. Is this correct???? if so how can that be?? because nothing travels faster then the speed of light not even gravity can.

 

[Jadzia]

I've built a simulation on the back of my accretion program, by wrapping the universe around on itself to close it, and redefining the force function to take the new topology into account.

For ease, I did this simulation on the surface of a torus T^2. So it is a 2 dimensional universe.

The result of my simulation is pretty dull however.


The broken symmetry begins with a deliberately displaced particle, which creates a "dipole" in the matter density.

From what the simulation generated, I can see that the high density area begins to draw matter towards it, and it grows in size and influence. While the low density area also grows in size because everything begins to retreat from it, but this happens more slowly and I suspect it may be a residual effect of the high density area drawing matter towards it, away from this low density area.

Either way, these two areas amplify in their intensity, drawing on the resources around them.

As the high density area gains mass and momentum, it begins to cause a chain reaction as it displaces nearby matter, which begins similar motions of accreting/retreating. Meanwhile, the matter on the fringes of the low density area also begins aggregating and exhibits the most complex dynamics.


All in all it behaves rather like a hole in one's tights causing a (lower density) ladder to run up through the tights. While the material on the fringes of the hole all rucks up (higher density) fragmenting into little clusters.

So there you go: Laddered tights, that's all it is.

 

[Hofner]

Although I'm no expert I'll try to take a stab at this. If there's anything wrong with my understandin of this I hope someone who knows more about it corrects me.

Using an analogy I saw an astronomer use once: he had a bungee cord about two feet long. Attached to the cord were four pens perpendicular to the length of the cord evenly spaced about four inches apart. The stretchable cord is the expanding universe and the pens are objects, like galaxies, located within that universe. Label the pens in order as A, B, C and D.

When you start pulling on the ends of the cord the pens will start moving away from each other. Each pen will be moving away from its adjacent pen(s) at a uniform rate ie; say pen A is moving one inch per minute from pen B, pen B is moving at the same speed away from C and the same for pens C and D. Note from A's perspective, C is moving away twice as fast as B at two inches per minute and D moves away at three inches per minute.

This is where Hubble's Law comes in. Given a uniformly stretching bungee cord or uniformly expanding universe, the further away an object is the faster it will appear to be moving away.

Now notice something else; the pens' relative position on the cord has not changed. If a pen started out at the middle of the cord it is still there and it will stay there no matter how far you stretch the cord. Same for a pen located one third of the way from the end of the cord, as you stretch the cord it will stay there one third of the way from the end.

Now if the pen is changing its position on the cord, this is movement that is independent from the movement due to expansion. I think they call this independent movement peculiar velocity. For example, in terms of the distance between the Milky Way and Andromeda galaxies, about 2.5 million lys, the movement due to expansion is so small it is cancelled out by the galaxies' independent movement due to gravitational attraction. These galaxies are actually moving towards each other. To observe the movement or redshift due to expansion you need to look at galaxies at a minimum of 50 million lys away.

If I understand it correctly the lightspeed limit only applies to this independent movement within the universe. The universe itself as a whole can expand at any rate it likes but within it you can't go faster than light. In other words if the pen located a third of the way from the end of the bungee cord wants to move to the middle it can't go faster than light and this is independent of the movement due to expansion.

Like most analogies this example isn't totally accurate in that I don't think real astronomers model the universe as being a huge bungee cord being pulled by an even huger fella. I don't know so much about how they model the universe; this is something that people like Shaw or Jadzia seens to know more about.

Thsi is my understanding of how it works and if I'm wrong I'd like to know; like I said I'm not an expert.

Robert

 

[think]

the three way hypersphere is more then multidimensional but just in the event I loose the disassociational effects of schizoidalism please - Kill Bill -

here the universe is infinite with everypoint at the very center of that infinite universe (given)

where is here? or there but now and then sometimes others exist inside the erratic definitions of thinking and the mind experiences schizoidalism

what ever really.,

the universe explodes as fast as it implodes about every infinite point in the infinite universe of universes and so forth thus the illusion of FTL travel of the univese of universes

strings break in the interum between subspace and the superverse but never the less they exist as well

motion means nothing to the infinite; the infinite is nothing without motion (sorta kinda) in neuon quantum divergences inside mind and matter and matterless minds.

So (class [LOL]) what the universe is, is what we want it to be before we know what we want it to be or was to have been.

 

[Shaw]

???